A neoplasm that arises from the ovary and originates from germ cells. Representative examples include teratoma, embryonal carcinoma, yolk sac tumor, and dysgerminoma. The disease is ovarian germ cell tumor (MONDO_0011366). Also known as: germ cell neoplasm of ovary, germ cell neoplasm of the ovary, germ cell tumor of ovary, germ cell tumor of the ovary, germ cell tumour of ovary, germ cell tumour of the ovary, ovarian germ cell neoplasm, ovary germ cell tumor.